Many recreational boats have planing hulls. When these boats reach a certain speed, the resistance of the hull dramatically drops as the boat is supported by hydrodynamic forces instead of hydrostatic (buoyant) forces. This is referred to as planing.
Boats used for wakeboarding and wake surfing frequently have a larger displacement compared to other recreational boats. Often wakeboarding and wake surfing boats have ballast tanks or bags positioned throughout the boat that may be filled to even further increase the displacement of the boat. This is used to create a larger wake for wakeboarding and wake surfing. However, the increased amount of weight, especially in the stern, creates a steep running angle of attack, which, among other things, reduces helm visibility, and increases the amount of resistance produced by the hull as the boat moves through the water. As a result, such boats may have difficultly getting on plane or may require very powerful motors in order to get on plane.
Some boats have overcome these difficulties by utilizing trim devices attached to the transom of the boat. For example, MasterCraft Boat Company of Vonore, Tenn., introduced an Auto Launch feature on their 2012 model year boats, which was replaced by a revised Auto Launch feature on their 2013 model year boats. The 2012 and 2013 model year boats both had three trim tabs attached to the transom of the boat, a center tab, a port tab, and a starboard tab such as shown in FIG. 2 below. The 2012 model year boats used profiles for a particular water sport and/or a performer. These profiles included a desired speed at which the boat would cruise while the performer is being towed. For example, if a wakeboarder wanted to wakeboard at 22 miles per hour (mph), this would be set as the desired cruise speed. The three tabs were deployed, and then as the boat accelerated to the desired cruise speed for the selected profile, all three tabs were retracted simultaneously when the speed of the boat reached approximately one half of the desired cruise speed,. In the 2013 model year boats, the center tab would be deployed, and then as the boat accelerated to get on plane, the center tab would be automatically retracted when the boat reached a set speed designated between 15 mph and 20 mph. The 2013 Auto Launch feature used only the center tab and did not utilize the port and starboard tabs, which remained retracted.